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Indoor cannabis growing with Sirius: one more time
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In this blog item Which cannabis seeds should you choose for indoor growing?The Super Sativa Seed ClubHow do you germinate your cannabis seeds indoors?The growth phase in indoor growingIdeal conditions for the growth phase of indoor growingSmart and cheap indoor weed growingFlowering indoorsIdeal conditions for the flowering stage in indoor cultivationEasy organic nutrition for indoor growingTime to harvest your indoor weed

Indoor cannabis growing with Sirius: one more time

We will have to wait a little longer for the outdoor growing season. Outside it is still cold and the activities in this time can therefore be counted on one hand. Last year we had a very bad summer. A major setback for outdoor weed and the end of my stash is in sight. Visiting the coffeeshop I want to avoid as much as possible, there you pay a high price for well grown cannabis. If there is any. Because I find the quality of the weed from almost every shop very poor. However, you can't blame the entrepreneur for this. Because of the ban a coffee shop has to buy cannabis on the illegal market and is dependent on what is available. Cannabis in a shop cannot be tested! Yes, you heard right. The law states that testing cannabis is processing it and that is prohibited. So you usually do not know what you are smoking. This gives us every reason and time to grow another round indoors. 

Which cannabis seeds should you choose for indoor growing?

For indoor growing you will find at Sirius a wide range of cannabis seeds of excellent genetics. There are regular promotions and offers in the seed shop, so keep an eye on the site. The variety you choose depends on your wishes and the use you want to make of the cannabis. 

  • Sativa dominant

If you like your weed energetic and uplifting, choose a sativa dominant strain. These strains generally have a longer flowering time and become much larger. Keep this in mind when growing in a tent, closet, etc. or if you want to harvest quickly

  • Indica dominant

Cannabis plants with predominantly indica influences generally have a heavier effect. These varieties give you more of a stoned feeling and can be used for pain relief. 

  • Little THC, a lot of CBD

If you would like to grow weed indoors with less strength, then there are also varieties with a low THC value. For medicinal use there are varieties with a high CBD value. Or varieties where the ratio CBD vs THC is 1:1 equal. 

Read also, CBD, THC and other Cannabinoids.

  • Autoflowers

If you want a monstrously large yield when growing indoors, consider growing an autoflower. This strain will flower on its own when it matures. When growing indoors you can give an autoflower a light schedule of 18/6 for the entire life cycle, so 18 hours of light and 6 hours of darkness.  This will give you an exuberant flowering and allow you to harvest more from one cannabis plant.

The Super Sativa Seed Club

For this indoor grow round we are going for the Lemon OG from Super Sativa Seed Club.  A cross of a Super Lemon Skunk X OG Kush. Most phenotypes from these seeds have the strong recognizable kush elements with a fresh lemon flavor. Many trichomes give this plant a high resin production. For me, the consumption of this cannabis has a positive influence on the severity and frequency of my migraines. The plant remains low and compact. Ideal for indoor growing with four plants. When it comes to quality, the Super Sativa Seed Club is always the right choice. The seed bank is one of the oldest in the world and has produced many legendary and cup-winning strains. A big shout-out to Karel and Kees from the Super Sativa Seed Club! I have had the pleasure of meeting them several times and they have often helped me with nutrition, seeds, information, advice, etc. Would you also like to know more about their organic growing methods for outdoor and indoor cultivation? Then The Organic Grow Book is the book you need to read.

The Organic Grow Book

How do you germinate your cannabis seeds indoors?

When it's cold outside, there is always a place in the house where the temperature is nice and constant. The room where the central heating boiler is located or a meter cupboard with heating pipes running through it are places in the house where you have a good temperature of 20℃ - 23℃ for germinating a cannabis seed for indoor cultivation. Personally, I prefer to germinate by the coffee filter method and the meter cupboard offers me the ideal temperature for germination. Once the weed seed has emerged it is planted in the soil and goes into the grow room. Here the temperature is pleasant enough for further growth. Nowadays we have more and more interactive television, including a box that regulates this. These so-called set-top boxes are constantly on and give off heat. If you put a tray on it with your seed pots or starter plugs they are nice and warm. Just keep an eye on the temperature so it does not get too hot and watch out for moisture in your equipment.

The growth phase in indoor growing

When the cannabis seeds have germinated the young seedling can begin its growth phase. At this stage the little weed plant does not need much water and growth nutrition. A little root stimulator when preparing the soil, that's it. When the soil is too wet you do not stimulate the roots to look for water, and in this way you hinder root growth. So regularly lift the pots to feel how heavy they are. In this way you can determine whether your cannabis plant needs water. Also take a good look at the plant itself. If the entire leaf with the stem hangs limply from the plant and is the pot light in weight, then it definitely needs water. If this happens briefly, this is not a bad thing. On the contrary, by doing this in a controlled way you will get a large root system. After watering the leaves will stand up straight again. If the pot is heavy, there will be enough water in it for the roots to absorb the nutrients through the water. If you see, however, that the tips of the leaves curl downwards then the soil is too wet and you should skip a round of watering for your indoor crop. 

Ideal conditions for the growth phase of indoor growing


  • Humidity 50% - 70% 

  • Temperature 20℃ - 25℃.

So don't keep the soil too wet in the growing phase but make sure you have a high humidity in the grow tent. This prevents the young plant from evaporating its moisture too quickly and drying out. The mentioned value for the humidity you will find in your home under normal circumstances. But by heating in the winter the humidity goes down. Unhealthy for humans and plants! 

If the humidity in your grow room or home is too low, you can increase it this way. 

  • Spray a mist of water into the grow room every day.

  • Place a few cups of water in the growing space.

  • Hang a wet cloth in the growing space

  • Make use of a humidifier

  • Place radiator trays, small trays that you attach to a heating radiator and fill with water.

  • Dry your laundry on a clothes rack.

Smart and cheap indoor weed growing

Do not grow more than five plants, even indoors. Therefore it is better to grow four plants in a square grow tent. Everything is neatly side by side and symmetrical, I like that. You let the four plants grow until you have an even canopy overgrown with few places where you can see the soil. This can take 4 - 6 weeks. It is then handy to buy a lamp with a dimming function. The first few weeks the young weed plant does not need a large amount of light. Half of a strong lamp is often enough. If you leave the lamp on at half strength, this is also half your energy consumption. Therefore it is best to grow with LED lamps. It is also useful to store rainwater. In a rain barrel or simply in a few buckets that you put outside. Fill small watering cans with it and put them on the heater to warm up. So you always have nice warm water, ready to use for your indoor grow. Don't just be concerned with cheap indoor weed growing. Do it sustainably as well. But most importantly, do it safely!

Flowering indoors

Once the lights are turned back to a schedule of twelve hours of light and twelve hours of darkness, 12/12, the flowering phase begins. The first signs of flowering still last 10 - 14 days. But from the moment the light schedule switches to 12/12, you start counting the flowering weeks. In the case of the Lemon GO, the flowering period would be 8 - 10 weeks. This margin of two weeks is quite wide. Sometimes people talk about: Harvest time 65 days. I think that's complete nonsense. The exact duration of flowering or the time of harvesting cannot be determined in advance. Simply because we are dealing with a living plant. But also the circumstances during the growing process have an influence on this. Always regard the duration given as an indication and keep a close eye on your plant. 

The first few weeks of the flowering phase is also known as the stretching phase. The cannabis plant will also increase in size when growing indoors in this phase and will thus cover the entire cultivation area. So don't let them grow too big before you start flowering. As flowering progresses and small buds are already forming, the plant needs drier air. 

Ideal conditions for the flowering stage in indoor cultivation


  • Humidity 20% - 40%

  • Temperature 21℃ - 26℃

The drier environment also prevents mildew, bud rot and other fungi. At the end of the flowering period, dry air provides extra resin production in the buds. By setting the speed of the extractor fan higher or lower you can also adjust the humidity in the room. Running an air-fan in the room also contributes to good air circulation and prevents stagnant air in the indoor growing space. As the flowering period progresses, keep an eye on the flowering nutrition for your cannabis plant. Look at the plant and focus on the producer's recommended growing schedule. This also applies to using a booster. With these boosters, boomers, shooters, etc. you can significantly increase your yield, but if used incorrectly they will backfire.

Easy organic nutrition for indoor growing

As mentioned above, we have four pots this growing round, each of 18 liters. Filled with a mix of soil and perlite. This is a volcanic rock. It makes the soil more airy and at the same time retains more moisture. This earth-mix can be bought ready-made, so you don't have to do it yourself. In this case we have only added Startrex.

The ease of use of Biotabs is great. Add to that the results and you will see that this is a super product! One Biotabs Starterpack is enough for the entire growing and blooming period for this indoor grow and PH measuring is not necessary. Sprinkle a little Mycotrex where the seedling will be placed and in each pot put 2.5 food tablets about eight inches deep into the soil around the planting hole. For the first watering, give Bactrex and Orgatrex along, then see what the plant needs. After repotting, spray the plants with BoomBoom spray and, in the bloom phase, give them the prescribed amount of Bio PK5-8. In the meantime, spoil them with some nice tea. That is all you need to do.  

Time to harvest your indoor weed

With the nutrition mentioned above you generally only give them water. So flushing or rinsing is not necessary. Handy if you don't know exactly when your weed will be ready for harvest. With harvest time also keep it simple with the harvesting itself. Just take out the LED and fan. Then cut the plants loose from the stems with a pair of secateurs and hang them upside down in the grow room. Leave only the exhaust on and let the cannabis dry gently. The carbon filter helps to keep the smell in the room. Under the right conditions the cannabis will be dry enough to start curing after a week or two. It does not matter whether you remove the small sugar leaves before or after curing. But do not throw them away and bake a space cake, for example. After two weeks the cannabis is ready for use. If you leave it a little longer to cure, you will notice that the taste becomes better and softer when you smoke it. 

So one more round of indoor growing before we start the outdoor season. Answer to the question: Can you grow weed indoors? No! According to the law it is not allowed and prohibited. So for the rest keep to the rules and do not bother or put anyone in danger. With this small-scale indoor grow, with inspected and certified equipment, you can easily and safely grow four plants for your own consumption. This way you will have a delicious supply of your favorite organic marijuana strain. 

Let it taste good!



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